Ornamental plants are not only a decoration of the yard but also food for many creatures. So you have to keep an eye on your plants and protect them from pests.
The black vine weevil is the bug that most often eats heuchera. To get rid of it, use beneficial nematodes in the spring. This is the safest and most organic way to control this pest.
Next, I will go into more detail about Black vine weevils and other bugs that like to feed on Coral Bells. Also, if you are interested in learning more about growing this plant, read the article How to Grow Heuchera Properly.
Black vine weevils (Otiorhynchus sulcatus) are the most common pests of Coral Bells. They have a small elongated black body and are most common in North America and Europe. This pest causes considerable damage not only to ornamental plants but also to agricultural crops.
Usually, these pests are difficult to see because during the day they hide underground and only come out at night to feed. They eat the leaves of heuchera along the edge chaotically. It can also leave holes in the leaves.
But it is not only the adults that destroy Coral Bells, the larvae do it as well. In spring, the female lays about a thousand eggs in the ground. After some time, the larvae hatch and begin to destroy the roots. If nothing is done, the plant can be left without a root system.
- If you see that the leaves are damaged along the edge or you can see holes of various shapes on them, these are damages from adult weevils. It is quite difficult to defeat them, so it is easier to kill the larvae.
- Use the beneficial nematodes Steinernema kraussei to kill the larvae and interrupt the breeding cycle. They are absolutely harmless to humans and animals.
- If the larvae have damaged the roots, dig up the bush and wash them all out with water. Don’t forget to kill the larvae. Then plant the heuchera in sterile soil.
- If the roots are completely destroyed, take cuttings and root them.
June beetles are large brown insects. They are mostly active in May-June when they are in the breeding season. Their diet is mostly leaves of trees and they rarely infest heuchera leaves.
After fertilization, the females lay eggs in the ground. When the larva hatches, it moves underground in search of food. If it finds the roots of Coral Bells from destroying them completely quickly enough. They can even destroy the root system of young trees.
- If you find that the leaves of your heuchera are drooping and the stem is not placed straight, dig the plant up. If there are no roots there at all, it is the work of the June beetle larvae.
- Dig deeper and you are sure to find a large white grub that must be destroyed.
- Plant the damaged stem in a pot of clean soil and place it in full shade to root.
- To avoid future damage and to prevent heavy spreading, water the heuchera with an insecticide containing carbaryl. This product is mildly toxic to humans and animals, but always follow the recommendations on the label.
Thrips are very common insects, with several thousand species. They affect a huge number of plants, including indoor and greenhouse plants.
They are very small insects that spend most of their lives underground. In spring, a female emerges from under the ground and lays eggs on stems and the underside of leaves.
Over time the eggs enlarge and small insects emerge from them. They feed on the juices of the heuchera. As a result, the leaves turn pale and discolored. If the spread of this pest is considerable, the leaves will die off.
- Clean up any plant debris under the shrub. This is a favorite habitat for thrips.
- Use blue sticky traps to kill the adults.
- Another way is to buy and use pirate bugs or ladybugs. These are natural enemies of thrips and will quickly destroy all their eggs.
- A final method is to spray the leaves with a watery solution of neem oil.
And the last of the possible killers of heucheras are caterpillars. There are so many different insects whose caterpillars can chew on the leaves of this wonderful plant and there is no point in listing them here.
All you need to know is that the caterpillars eat the leaves along the edge or leave holes in the leaves. It is not always easy to spot these pests because many of them hide from birds under the leaves during the day. They only come out to eat at night.
- If your heuchera’s leaves are damaged, inspect the entire bush thoroughly. Look under the underside of the leaves. If you find caterpillars, destroy them.
- Dilute 1 teaspoon of dish soap in half a gallon of warm water. Add 1 tablespoon of molasses and mix it all up. Spray the leaves with this solution.
- The second way is to mix half a gallon of water with a teaspoon of dish soap and 1 teaspoon of vegetable oil. Then add two or three crushed garlic cloves and mix everything thoroughly. Spray the plant with this solution.